If you want a luxury brand V8 convertible the car you should be looking at is the BMW M3. It would be nice if Lexus was serious about competing with BMW and had a coupe version, V8 engine & manual transmission option across the board but they don't.

If you want to stick with Lexus then yeah IS 350C F-Sport or an IS-F is the way to go.

 

Aimgain kit is about 7k not including the body work to go with it. better off getting the IS-F

 

Lexus IS-F convertible

Price: $65,000 (estimated)
From the rumor files is the long-awaited IS-F convertible. It's said to be coming in 2013, possibly this summer, and the pundits forecast an otherwise unchanged folding hardtop version of the IS-F sedan. That means at least a 5.0-liter 416-horsepower V8 engine and an 8-speed automatic transmission. The drop-top should inject more excitement into this capable if somewhat sterile sport coupe.

This just posted on MSN is apparently old news from last July. Here's more info if you haven't seen it.

Spied: 2014 Lexus IS F Convertible

 

If they made a convertible isf then I would go with that. Really I'm just looking for a car that the body kit would fit and a convertible. haha idk just a little thing I've always wanted in a car.

 

Well there is the possibility of the 4.3 liter V8 found in the SC430,GS430 and LS430.

These engines have been around for awhile and have lots of aftermarket support for strong rods, pistons etc. You wont see any horsepower increases over the 350, but you'll get about 50lb more torque AND you can build the motor for boost and make HUGE power.

Supposedly a guy swapped the 4.3 into his IS250 with minimal headaches. He said that he just included the ecu from the new engine and that it was able to communicate with the other systems no problem. He basically coined it as a plug and play solution.

I did check the motor mounts and they are exactly the same from IS350 to GS430, so it should techincally fit. I'm just a bit concerned about the true plug and play capability of doing something lik ethis. I gurantee though, that if my motor ever goes, I'll be giving this a try.

 

The only way I could see a 3UZ-FE being a nice plug and play setup is if you used the wiring and ECU from a 3GS GS430. Other cars and model years will be a bigger hassle.

2UR-GSE would be not too bad to swap, but still money.

Jeff