there isn't any huge difference between dvi and hdmi for this model, you can't pass sound over hdmi with this particular macbook edition. Both adapters are really cheap in fact i just bought a mini DP-dvi for 1.99 (shipping included) and it works great.
Of late i've seen very small minidp-hdmi such as
this one here you can see the dongle is only as large as an hdmi cable, instead of the giant block with dvi. I've even seen
these cables directly from mini dp to hdmi either one will work though, dvi or hdmi. I feel that dvi cords are thinner and more flexible than hdmi
I would also recommend the used or refurbished route for lcd panels. You can get really nice monitors for cheap. I got 2 22" ASUS LCD monitors (with speakers) for less than 100 bucks each. no problems with either, they came with all the cables cds and original packaging. Maybe they were just a good deal but twice in a row 4 months apart, I don't think its coincidence. There are cheap lcds out there. as for recommendations... I like dell ultrasharps, they typically have VERY nice stands, many have Picture In Picture, multiple inputs, and best of all they have built in 4port USB (2.0) hubs. really great monitors,
take
this here 24" dell its 24" 16:10 display (1920x1200 pix) inputs: 2xdvi, hdmi, vga, composite(yellow rca), component, s-video, displayport, and 4 usb ports, a card reader(cf/ms/msro/msduo/xd/sd/mmc) picture in picture??!?!?! and it rotates 90˚ swivels left and right, angle up and down, and you can even easily raise and lower the lcd stand, and if you don't like the stand(dont see why you would't) its vesa compatible and look 200 on ebay!! those are beastly monitors