I'd be amazed if any of the smaller saws had a standard mitre slot, and it doesn't really matter anyway, but hey, movin' quickly on...
... If you want to cut up sheet stuff, get a track saw. Ideally either a Festool or a Makita. You can also get a knock-down assembly/cutting table from CNC Design in Wrexham, for around 150 quid delivered (they also sell the dogs to use). It's a poor man's MFT table and will allow you to cut a lot of things with excellent accuracy. If you go that route, a 3m rail is under 200 quid (from Makita - Festools run on it too), which means you'd be set to cut up sheet goods lengthwise as well as crossways*.
Tracksaws occupy one size-4 Systainer when put away, plus somewhere to store the bag for the rails. Tablesaws just sit there in the middle of the workshop, waiting for you to walk backwards into them (whereupon they snigger, I'm certain of it).
Beware though: unless I misunderstand how it operates, you can't use an MFT arrangement with a DeWalt tracksaw, because it has a rubber strip on both edges of the track (i.e. the track is reversible). This is pretty dumb on DW's part: although it makes no difference really when cutting up 8'x4' sheets of chipboard flooring, you can't align the rail with confidence against stops, which you do with an MFT. Most of the inexpensive tracksaws are probably unaffected by this limitation though.
I have the sliding carriage for the TS 200. There's no way you could use that for anything bigger than a cut of around 70cm, because the track is too short, and there is no support for sheet materials hanging out to the left of the carriage. A full size panel saw has a very different track and carriage - the track will be about 15 feet long for a start, and it will move and cut a full sheet of material with ease! Someone is sure to pop-up to dispute that ("I cut a panel 20 metres long on my TS200"), but honestly I wouldn't consider doing it that way, especially on my own.
Hope that helps. but in the interests of balance, find an Axminster shop near you and have a look close-up at the TS200 and TS 250. I think they're good value, especially the TS 250.
But also look at Makita and Festool rail saws while you're there. That's a tough: The Festool has a riving knife and a range of good accessories. The Makita has 2.5mm deeper cut**, a scoring feature (which works well), and an anti-tipping system to keep the saw planted on the rail when cutting bevels. and it's a bit cheaper. Both work really well and many (but not all) accessories can be used with both systems.
I have a Makita, I like it, but I'm torn as to which I would buy again if I had to, as there are so many good things about the Festool. You'd have to decide for yourself.
Or get a tablesaw...
Have fun!
E.
*obviously a 3m rail won't magically work on a smaller table. I use a bit of 8x4 polystyrene insulation to rest the stock on, and cut on the floor.
**Festool, of course make two sizes of rail saw - the TS 75 is quite a bit bigger than the TS 55 (which has a 160mm blade). The Makita has a 165mm blade as standard, but will work with 160mm ones..