Just get a Featherlite 24ft with the heavy duty 4,500b axels and you will be happy as a Bonnie!
I too vote for the Featherlite. A VERY well built trailer that will never let you down. Because we use our Featherlite for the business (to pick up and drop off customer GT's), we've probably loaded/unloaded 10X more than 95% of the folks on the forum. My opinion is that it is far, far easier to winch the cars into the trailer. Our winch is offset to align with the GT's tow hook and we have a wireless remote. Literally 2 minutes to load a GT - another 2-3 minutes to strap the TIRES down. Here's our procedure.
1. Park truck/trailer on level to slightly up hill angle. If needed, with trailer still hitched, use tongue jack to create a slight incline.
2. Drop door, let out winch line to approx. end of trailer.
3. Pull GT up to ramp, more or less centered, drivers window down, engine off, key in position 1 to unlock steering wheel, neutral, set parking brake.
4. Exit vehicle, connect winch to Cool Tech Tow Strap, use winch remote to remove slack from winch line.
5. Release parking brake. Use wireless remote to winch car in. Make minor steering adjustments as needed to perfectly center the car. As you are outside the car, you can see everything perfectly and stop/go on the winch cable as often as you'd like.
6. Once in, secure first over-the tire strap and ratchet down. Release 2-3 inches of winch cable to add slack. Secure the other 3 tires. Reach in car, turn key to off.
7. Turn master winch power off (just in case!)
Unloading is even easier.
1. Again, park trailer on slight incline. Induce incline with tongue jack if needed.
2. Set parking brake on GT. Release all 4 tire straps. Release parking back and GT will roll back 2" removing slack in winch line.
3. Use remote to let line out of winch, and GT gently rolls out of trailer.
4. Set parking brake and remove winch line.
The loading/un-loading process is child's play. Granted, there's a little up-front investment needed in the winch, wireless remote and E-track. But that's what make the job so easy.
Regarding the trailer and choosing axles, bigger is not always better. If your load is typically GT-weight or less (and maybe a set of tires or similar), then you will likely prefer the standard axles. The upgraded axles will make the Featherlite 2-3" taller than the standard (3500 lb x 2) axles. I have the standard axles and the back of the trailer is really low and I don't need any ramps to load even the lowest GT's. My buddy has the optional axles and he needs to carry and position ramps with each load/un-load.