You will be hearing this a lot in any of the responses to your thread, but YES!
! Boots, boots, boots!! Try on a crapload, and make sure they fit right! Then think about other gear! If the budget is tight? Still,... BOOTS FIRST!
If you've got good fitting boots, they'll even improve your rental board experience until you're ready to buy!
Having said that,... here's a site with a TON of board info. It will take a while for you to go thru and familiarize yourself with it all! Good Hunting!
snowboard community forums - Ippy's Snowboard Buying Guide - Page 1
Here's two more from this forum;
and since this info will come in handy before & after you do buy a board;