How large is large-ish?
Dunno if any are actually compatible with the 630 series, but LC Slot VidCards aren't much to write home about, AFAIK:
http://lowendmac.com/video/lc/index.html
The Q630 was an odd duckling, an LC in wolfish Quadra clothing and sheepish I/O in the expansion slot/onboard Video Department. I think of it as the Quadra family Parallel to the IIsi in the Mac II series. Thank heaven they put a Meg of honest to goodness, real deal VRAM on the 630 MoBo. Vampire Video on the IIsi was the absolute pits.
That said, you're going to need a MultiSync or Mac-Friendly-Grudgingly Compliant LCD to get much use out of the 630, IIRC. You've got standard LCD compliant 60Hz VGA at 640x480 and 800x600 only IIRC.
Somewhere in the LCDs vs. Macs threads you'll find the lineup of KDS/Radius LCDs I've collected and pics o . . .
. . . well there
might be some pics of those and the others in those threads. :-/
The only resolution I ever found useful on the beloved Quadra 630 was 832x624 traditional 16" Mac res. at 8bit for Illustrator etc. at home.
Full Screen TV/Tuner image at 640x480 in 16bit was gorgeous. It was a far nicer/snappier image in pixel-doubled progressive scan on a 17" Sony Trinitron Multiscan Monitor in the rug rat's room than the interlaced analog scanned image on the 15" Sony Trinitron TV in the master bedroom.
I used the P6360 replacement for the Q630 until five years ago to watch movies on a 21" CRT. Me likes 32" 720p!
edit: @ MacDrone: They were pretty much bad enought that nobody really wants to know about them.
If there's an error on one of those LEM pages (few lack one) there is one card listed that will do 1024x768 in 8bit, the board's name says "Color" but the article says grayscale. Go figure.