H61 and H67 will run any single GPU just fine with no loss in performance, double slot cards will also fit on those boards just fine. If you plan on getting a lot of expansion cards you probably should look for a full size ATX board. MicroATX is fine if you aren't going to use a lot of cards, an don't need the extra expansion room. Unless you want to SLI or Crossfire down the road you don't need to have more than one PCI-E x16 slot. Some H61 and H67 boards might have SLI or Crossfire support, but it is not available natively on those chipsets. I don't know of any models off hand that do.
Boards that are SLI or Crossfire capable do tend to be more expensive, I'm not sure if you could fit one into your tight budget, not unless you want to go for a cheaper graphics card, and lose out on some performance until you can afford to upgrade to a better GPU, or add a second one. Generally speaking, it is usually better to have one powerful graphics card rather than run two lesser cards. SLI and Crossfire tend to complicate things, you are more likely to run into hardware, problems, heat issues, and driver problems with those setups than you would with a single card. It may not be worth the hassle unless you need a lot of GPU horsepower to drive an ultra high resolution display, or multiple monitors. With a 1600x900 monitor, pretty much any worthwhile dual GPU setup would be overkill. A single mainstream card would be plenty for that resolution, you would only need a second if you really, really wanted to max out Crysis 2, Metro 2033, or Battlefield 3.