First off, I really would consider saving yourself money and not bothering with H&R Block. It seems like you have a pretty straightforward situation.
Unless you have any investments in the US or any other complicated tax situations, it sounds like you will simply need to fill out a 1040, and a 2555-EZ (foreign income exclusion). You can find both of these forms on the IRS website. You don't need to include anything in place of a W-2. I just used my payslips to figure out my earnings, and used the exchange rate on the embassy website to convert to UDS
http://www.usembassy.org.uk/irs/irsfaq.htm. I have held on to my payslips in case I do ever get audited, but when I went to the embassy to turn in my taxes, they said they didn't need to be included.
I know a lot of people use TurboTax, which sounds like a good option. I just fill mine out with pen and paper, since I can't e-file (it won't let you get around not having a social security number or ITIN for your non-resident, foreign spouse.) You can then either send your taxes to the Austin service center, or the US embassy. With regards to the 2 month extension, the woman at the embassy just wrote 'tax payer abroad' on the top of my 1040. Easy-peasy.
Don't forget, that depending on what your bank balance is here, you also may need to file a TD F 90-22.1 to the treasury (report of foreign bank and financial accounts). I think this is due in June.
The embassy website is pretty informative. Between that and the IRS website (in the forms library, there are instructions with every form), you should be able to figure everything out. Fill out the 2555-EZ first, and then you will have all the info for the 1040. You enter your foreign earned income where you would normally enter the info from your W-2, and then if it's under the threshold, you exclude the entire amound further down on line 21.