SIPs work if you are just modding or swapping out everything except for the base/swithplate. (in cherry/gateron style housings). The bottom housings are all the same with those two, you can go from linear to tactile to clicky all with just changing out the stem & spring (if you want a different weighting).
What form factor are you looking for (40%, 60%, TKL, Full Size)? Some PCBs/kits have SMD LEDs AND hot swap sockets. both issues resolved.
Or if not going with hot swap sockets, go without plate, just PCB & switches lots easier to swap out individual switches without having to undo them all. plus there are a number of switches that can't be opened when in a plate even if the plate is made for switch top removal. (kalith, outemu, etc..)
I think if you get a cheap board to do what you want to do, you'll have more issues than starting out with a platform that's easy to swap out components, if that's the main goal. (i have a magicforce 68 and can vouch for that)