Yeah, the roadriders are great tires. The 4.00x18 is on the edge of being too wide for a stock 750 rim, but it can be done. The best option would be to lace a wider rim on your hub, but things get expensive quick in that arena.
The roadriders are a much more modern looking tire than the firestone, and they perform well- I use them on my 750, and have put them on dozens of SOHC 4's.