This may be blatently obvious but I'm buying rims and tires. If i don't put the tpms sensors in them the tpms light is going to trip right?

Correct, but why wouldn't you have them installed in your new wheels? The TPMS really works, if any tire on your car drops below 29 PSI the alarm will show on your dash. The TPMS could easily save a tire and your rim at speed!
Gary

here's another question. i have an 03 which doesn't have tpms. if i put an 05 gauge cluster in, will it be looking for tpms?

my stock rims have snow tires and have the sensors in them. The new rims arrive with the tires mounted and balanced. This now means I have to buy another set of sensors and the tires have to be taken off sensors installes and remounted and balanced. PIA!!!

i have an extra set of tpms that i got when i bought some stock 18's. i was thinking about keeping them because i was going to change to an 05 cluster. but after seeing all the work it takes to modify an 05 cluster and to put it on an 03 i think i might sell it instead. PM me if you are interested.

pm'd

would anyone know how to check if the tpms works or not? i have a set but since my car doesn't have it i would like to find out if they work. any help would be greatly appreciated.

I still suggest you take the sensors out of your winter tires and have them installed in your new rims/tires, it's just like changing valve stems. If you buy another set for your new set up you'll have to get them reprogramed for your G....more and more cost. Who's on first?
Gary