You can use any normal guitar to play lap slide. All you gotta do is take it from its normal position, resting on your thigh or hanging from a strap, and turn it 90 degrees so the back rests on your lap, with the strings facing up. Seriously. I do it occasionally with my Strat, in standard tuning (which, believe me, is a lot harder to do, and requires far more precision than I usually have ;-) ) when a particular song needs it, and I have a Les Paul-style electric that I have set up tuned in Open E, and some times Open D, that I can play either standing or lapstyle. Though not very well, ha-ha.
You can also play an acoustic the same way. The things that you might have to change are:
1) Tuning. The reason Hawaiian lap slide guitars were called "slack key" is that they were tuned down to an Open G or other tuning, as opposed to an Open E, which reduces string tension on the neck. Open E puts a pretty fair amount of stress, even on a neck with an adjustable truss rod, and often leads to broken strings, especially the G and b. I can't tell you how many strings I broke on my first cheapo acoustic, trying to play it in Open E; when I got a guitar with a better neck and properly adjusted truss rod, I broke a lot fewer strings, but still remained nervous tuning 'em up that high. I shied away from slide for years because of it. Other reasons to tune like we typically tune CBGs is you can get nice major or minor chords at the 3, 5, 7, 9 and 12 frets, when you bar the slide all the way across the neck at those fret positions, depending on the tuning and string gauges, that work well with most blues songs. Different string gauge sets can also give you different slide tones: wound strings sound grittier and deeper, unwound strings sound more metallic yet sweeter.
2) String height. This is pretty easy on an electric guitar, because most have adjustable string saddles and / or bridges. Most people like a low action on their electrics, so as to play faster; if you're going to play one lap style, then you might want the bridge saddles set quite a bit higher than "normal," so the slide bar doesn't impact the frets. On acoustics, it is both easier and a lot harder to adjust string height at the bridge /saddle. Harder, because the bridge is typically glued tot he fret board. Easier, because you can either 1) shim the saddle with very thin pieces of wood veneer to raise the action (string height), or 2) replace the existing saddle with one that is higher.
3) Technique. This is the most difficult thing to learn. Playing slide takes a different technique than playing fretted. First thing is, you have to move the slide bar over the fret, not behind it. You don't press down near as hard as you do when finger fretting. If you know how to do finger harmonics, then that is about the same pressure you want when playing slide: the slide bar lightly resting on the strings. It also will sweeten or improve your tone, if you can learn to lightly touch the string behind the slide bar with one or more fingers, to dampen the vibrations between the slide and the nut; you want the string vibrating from the slide to the bridge / saddle. Or you can just let the slide do the work, and get that old slightly scratchy Delta blues sound, which is less precise. Then you can move on to playing the way Duane Allman often did, and Derek Trucks often does, in standard tuning, and using the slide on individual strings, This is THE most difficult slide technique to learn, and one which I will probably never master ;-).
Long winded answer to a short question, eh?