I'd highly recommend staying away from the typical finance places (Chase Health Advance, Carecredit). I reviewed their ratings with the Better Business Bureau and their complaints seemed pretty typical to those low-level "cash-stores" you see in strip malls. The most common complaint is that if they make some sort of error (if automatic billing misses the deadline due to time-zone differences, or their operator hits a typo, or any other mistake on their end), you're the one who's penalized (huge late fees, 0% to 29.99% interest increase, heck - there's even a penalty for paying it off early!).
My advice (and what I'll be doing for my HT this May) is to finance via credit card. Go to a site like nerdwallet.com, and find the visa/mastercards that offer 0%APR on purchases for an intro period (21 to 15 months). The government has loads of consumer-protection regulations governing these guys that don't extend to the private financing institutions like chase and carecredit.