This is a great one to get: https://www.amazon.com/gp/product/B089KT3FG9/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 I can verify this seller has the genuine TI chips in it and they work great. I would highly recommend it, but you have to make sure you get the ones with the TI chips as there are knock off versions out there. You won't need anymore than this amp for SSF, and also I recommend starting with a 5.1 setup. If you go with 7.1 but you only have one bass shaker, then either your fronts or your rears will not utilize the bass shaker. In my testing, having a 2 higher quality dayton speakers and a bass shaker is way better and simpler than having 4 of them -- it's very difficult to determine where the sound is coming from anyway.

this one specifically has the best quality and features for the lowest price. Some of the cheaper ones are awful.