That stem actually looks long to me, but I did intentionally search out the shortest stems I could find in an effort to keep the sensors from sticking out of the wheel too far.
I ordered my TST507 through infotechrvsolutions ($220 for 4 sensors). They were drop shipped directly from TST. Mine arrived without the installation tool. I emailed Infotech...they nearly instantly apologized and called TST who sent out some tools the same day. Great service from both companies. I chose to order from Infotech as they were slightly cheaper than the TST listed price. I have heard of people calling TST directly and getting price matching from them.
'04 GMC Sierra 2500HD, CCSB, D/A, MaxBrake, B&W Companion, Retrax Pro, AR Power Steps
2013 Rockwood 8289WS w/Diamond pkg
1969 Camaro RS/SS Convertible
Dad's old 1968 Empi Imp (recently recovered from under 21 years worth of boxes/dust)