SSDs use the same flash memory as CF cards and USB memory sticks, so I don't think they wear out less fast than CF cards.
Check other threads in this forum about using disks larger than 4GB. It's dangerous if you don't know what you are doing.
Actually, the HDD quality NAND flash, have been rated up to around 1 million writes.
Off the top of my head, Sandisk rates their CF NAND at around 10,000 writes. (Per sector).
And as for the using larger than 4GB, *ALWAYS* make the boot drive, in the FIRST 2GB. That way you can safely load all your system patches and other guff safely, then after that, once you have patched TD64 or NSD, you can use LARGE partitions.., but always remember, the larger the partition, if it needs revalidating, the longer it takes.
Thats why we usually recommend making the BOOT partition <1GIG, heck, even a couple of hundred megs will do nicely as a boot.