I primarily record drums and will give you my opinion on your situation:
For interfaces I would highly recommend the Clarett 8PreX - the Air mode is excellent and sounds very much like ISA preamps. I would use one of these and then run the Motu as additional pres using ADAT once you upgrade. I am able to record 16 tracks at a 32 sample buffer with plug-in enabled play back on guide tracks.
If you are going to purchase a snake make sure you get one with decent cable in it, many really cut corners by using very light gauge wire. For cables look for something with 2 conductors that are at least 24 AWG with 95% spiral copper shield with a capacitance per foot rating of between 18 and 26 pf per foot. That will ensure you are getting a good signal back to the preamp. You can't go wrong with Neutrik connectors, and if you need to save REAN are also good, but they won't survive years of use as well.
If you are going to leave the kit in the room while recording other instruments the dimensions of the room itself will really play a huge role in what you need to do to the kit. My old room was 12 x 14 with 8 foot ceilings and I had to pretty much take the kit down so it wouldn't sympathetically vibrate with other instruments while doing critical recordings. My new room is 28' x 34' with 14' ceilings and this is no longer a problem. A nice middle ground will be taking the cymbals off and laying them on a carpet or packing blanket (or putting them in a cymbal bag) and placing a heavy moving blanket on the drums. Always disengage snares when you aren't using the snare drum too, not only does it keep it from vibrating it also makes your resonant head last longer.
For mics I would suggest the following as a great starting point:
Kick: AKG D112, Audix D6 is also great but really geared towards Rock, the Beta 52 has a sound that some people like, I am not one of those people.
Snare: 2x SM57, Audix i5's are great too but more hyper cardiod and build like a tank if you are recording a drummer with poor stick control it might be good to have one on hand.
Rack Toms: Audix D2 - Sennheiser 421's are also great and I use them now and again, but 1 costs as much as 3 Audix mics and I find they need more EQ
Floor Toms: Audix D4 (14" and 16") or D6 (16" or 18")
OH: I prefer LDCs here and love Advanced Audio CM414 - to my ear they sound identical to an AKG 414 and are 389USD each. For SDC check out the oktava MK-012 for and excellent mic that is reasonably priced. If you are able to solder as well the 012's can be upgraded with addition resistors and a new transistor that will bring it inline with a Schoeps cmc6 (at least I couldn't tell the difference in a blind test). I have never tried Lewitt but Warren loves them and that's enough for me to say they are great too.
ROOMS: Get a good pair of mid-market ribbons like the Bumblebee Pro Audio RM-5 or RM-6. These are great for rooms as they keep the cymbals nice and smooth.
What kind of drum kit did you get?