i generally play by the bridge, and the tension is just perfect. But when I "rock out" a little more, and don't have to play too fast, I get close to the neck and really attack (kinda like Entwistle). On fretted this was fine, but now on fretless all I get is clack. What strings can maintain a reasonably aggressive sound (kinda like light gauge strings) but with enough tension to leave the fingerboard alone
I use stainless, but the nickels are great strings too. They're a little less bright, smoother feeling, and only have a bit less tension. I'm not a fretless player, but I'd imagine they'd work great for that application. Honestly, the SS Lo-Riders feel pretty smooth to me, especially compared to Rotound SwingBass strings. I hate to cop out, but you really need to buy a few different sets and just see what works best for you. What constitutes "good strings" really depends on who you ask. It's so subjective. There are guys who post on TalkBass whom I really respect who have completely different opinions on strings than I do. Rock on.
a friend of mine uses the steel 'riders on a fretted, and I love the deep tone you can get with some higher gauge ones, so I'll definately give the nickel a try