Welcome! I'm just finishing up my first year this year so I was in your shoes a year ago. Feel free to PM me with any questions.
Here is my $0.02 though. I bought a sedan only bc they are cheaper than coupes and my start up budget was tight. So far the differences in them (IMO) is the sedan is a little more lazy to respond in the corner and generally is a little tighter. They also are a little bit roomier if that's something you need. If you do go this route, make sure that the chassis is a 4 bar instead of a 2 bar. This means there are 4 vertical roll bars behind the driver. A little more weight but its safer. With the motor 1200 vs 1250 sealed...I went with a 1250 just bc I'm not a motor guy but have raced against 1200 and they are just as fast. I would suggest to do a compression check on any motor that is used just to make sure your getting a good one.
Driver gear will be anywhere from $800-$1200. Fire suit, helmet, HANS, gloves, shoes, etc.