I would go with
this one. It is the R4i Gold and is officially supported by the Wood firmware which has RTS among other features. While the DSTWO is technically the best it will drain your battery like crazy in sleep mode due to the onboard CPU. As for resellers, apparently modchipsdirect.com is pretty reliable and ships from the USA. No paypal support though they do accept credit/debit* cards. I just ordered one from them myself early yesterday (thursday) morning and it is showing as Complete but it hasn't shipped yet.
*Assuming the debit card is a standard visa/mastercard/amex/discover one that also works as a credit card, of course.