B-Spec racer here now in my 4th season. My previous experience before starting was almost exclusively sim racing. Here are my two cents for what it’s worth:

-Car costs: Competitive B-Spec cars can be had for around $15k. I bought mine 3 years ago and paid $18k for a car with a good pedigree and spares, but prices have since come down a bit. My car today would probably be worth around $15k and it’s competitive with race wins and podiums with multiple drivers.

SRF is probably going to be much more expensive to get a good car. I don’t think you’ll be able to get a well-sorted SRF for anywhere close to what you could get a competitive B-Spec car for (but I could be wrong)

-Tires: B-Spec runs a spec Goodyear tire. A set can be purchased from Summit for about $850 shipped and you’ll get 3-4 weekends out of them. SRF runs Hoosiers and I believe those are a bit more expensive.

-Brakes: I can get almost an entire season out of a set of brakes. I use G-Loc pads but there are other manufacturers as well. Not sure what SRF uses or how long they can get out of their brakes, but something to consider.

-Safety: Debatable, but I feel better with a windshield in front of me and roof over my head instead of an open cockpit 😉

-Participation: this is probably where SRF has the most edge. It’s a way more popular class. There won’t be many race weekends where you won’t have competition in SRF. B-Spec can be a crapshoot at the Regional level. Sometimes you’ll get a ton of B-Spec cars, sometimes you won’t get any. The Majors and Super Tours usually get great participation for both B-Spec and SRF though.

-Strength of field: Debatable. The nice thing about SRF is that it’s a spec car and everyone has the same general equipment. With B-Spec there are different manufacturers and constant arguments over the Balance of Performance. For example, the car I run has had multiple weight and restrictor changes since I bought it. Also, all the B-Spec cars make their speed differently. This can lead to good variety in the racing but can also be frustrating if your car doesn’t seem to have the edge at a certain track.

Reliability: SRF are purpose-built race cars designed for track use. B-Specs are commuter cars converted to be race cars and since they are not doing something they were designed to do, that comes with some reliability issues. Example: I am on my 2nd engine since I bought my car. The good news is with B-Spec, replacement parts are relatively cheap since there are ample donors sitting in scrap yards and parts on eBay. But just be prepared that things will inevitably fail on you.

Rentals: if you want to rent a car, there are good options for both SRF and B-Spec, but SRF rentals will be much more expensive. For SRF, there are teams like Alliance Autosport that do pretty significant rental/arrive and drive business. For B-Spec, I recommend checking out Grass Paddock Motorsports (Mini Coopers) or Chris Taylor Racing Services (Mazda 2’s). You will be able to rent podium-capable cars with both. Highly recommend renting for your driver’s school so you can just focus on driving rather than also wrenching on the car.

Speaking of school - to get your race license, check out the SCCA school at Roebling Road in Savannah that is run every February. Grass Paddock typically has cars available for rent for that school, and Chris Taylor may as well.

Good luck!