@JustinSj you have to decide what you think is the best option for you. As I said different people can and will make their own recommendations based on what they themselves own or have tested.
I merely am sharing findings I have come across in testing
lots of different installation possibilities and
various tactile hardware over the last 2 years. All I can highlight to you, is I want the best possible immersion from tactile and using multiple effects. I have sought after a way to bring it unlike conventional installations and push the boundaries in what we can get from it. I tested 6 different options in small tactile units and exciters before choosing what seemed best.
Let me be clear, the exciters and doing a multi-channel configuration for additional body zone contact and the benefits they bring is a crucial element needed to achieve that goal.
They are cheap, they are easy to install, they allow a user to easily get into tactile
We can and as I will demonstrate then expand what these bring with the benefits of adding the more expensive large BK or Earthquake units at a later time. This to then fully and properly utilise the lowest bass frequencies and build effects specifically for these to work in concert with the exciters and to also expand the number of usable effects.
Frequency Range & Detailing
From the extensive testing I did, the 40w exciter will outperform other exciters and most of the budget tactile when it is directly mounted to the seat. I expect anyone will be surprised by the energy they have with limited wattage and being so tiny. It is important to purchase the correct model and it has been shared on the forums here several times.
A unit being bigger or higher wattage with 50w or 100w does not specifically mean it will be better and also when we take into account how/where they are installed and their primary energy gets to the user. Many of the popular budget tactile have quite restricted output in their operating frequency range. As stated above by owners with 55Hz or 80Hz limits. The best units for detailing of mid-high bass are the exciters and also the TST models yet these are quite expensive. BK units are better for low-mid punch but not for detail over 60Hz range they start to drop off.
Important Factors
The more operating range we have in a unit, then the more definition we can place into different effects or use the wider range to give different effects their own sensations to help separate them. I have demonstrated how harmonics operate and even effects with low Hz also generate detail from harmonics to much higher frequencies.
Someone with a unit that is less capable in frequency range
will not get the full potential detailing we can with the exciters and that's before we even take into account factors of direct installation to a body zone and then combining zones. This compared to an often larger budget unit, having to transfer its energy over a further path and that energy also dispersing to other places.
Controlling the flow of tactile energy is another "crucial factor" to getting the best out of the units installed. This and the de-coupling of seat/pedal platforms with using isolation are important factors in a tactile/rig build.
Amps
This thread covers many amp options from budget mini amps like Knobsound / SMSL to larger amps, to multichannel amps to AV Receivers. The Behringer EPQ304 is a good amp, small and been selling for years, so is a stable option but it isn't as quiet as I would like and will see to reduce its fan noise. Might someone prefer 2x mini amps like Knobsound or SMSL, maybe. Some other 4 channel options are available but we start to get into higher money and high wattages to power units that need very little wattage. The AV Reciever option is great value but how many people want the big sized amp (again to drive tiny exciters) and then having to learn/deal with all its onscreen menu options to alter/control channel volumes etc
Effects Experience & Combined Efforts
The main difference with the options you have is that the one I am recommending, you can have access to effects I am creating. The same I will apply on my own high-end build by using specifically the same installation method and same units. Therefore installing them is going to ensure users will get very nice quality effects, to the benchmarks I seek to enjoy.
You can of course, buy 2 or 4 units now and do your own thing to get into tactile. It's optional if you want to take part in my own experimentation and effects testing.
Already a limited few people have started with installing the 6 channel installation needed to their seats. I am sharing these beta effects currently within the last couple of weeks. I send them updates of new samples as well, based on feedback and we share/discuss their own inputs or applied changes. Some others are seeking to join in and are waiting on getting the hardware to have it installed. So gradually it seems some people are taking interest in this concept or approach.
*Note, for my own effects, six channels are needed to properly experience and use the effects being created. Some effects go to specific channels and we use them to separate the effects. Some effects use multiple channels at once for the body zones. Different approaches are being tested and seeking peoples feedback. Four channels is not enough if wanting to participate and use my own experimental effects.