Can you buy the home a few months before ER? That would alleviate the income issues right off the bat.
As for the credit score itself, others hit the nail on the head. Go find out what your score is. Then find a mortgage broker you can talk with who will give you the rundown on which scores typically qualify for the best mortgage rates.
With that information, you can figure out whether or not its in your best interests to "find" a few loans to pay back. I know about a decade ago I took out a personal loan from the bank (back when banks actually offered unsecured personal loans) - put the money in the bank, and used that money to pay back the loan. The interest I paid was about $250 total, but it was *well* worth the improvment of my credit score which was my only purpose for taking the loan out in the first place.
Sometimes things like car loans, due to such low interest rates, can be very advantageous when it comes to building credit for home purchases. Not to say it's the only way, but I wouldn't say "fortunately I could pay cash" since car loans are typically low interest rates which can enable you to both invest the assets elsewhere and allow you to build credit.
So if you need to build credit, you might consider getting a small loan over at Prosper.com (I have a group there in case you're interested - just PM me for an invite) - start it off at 10% max and see if it gets funded. Then pay it back in half the time and watch your credit score improve.
However, if you've been using at least one credit card for a long time, and have a bank account that's been around for a while, and you have no negative things (late payments, etc), then you're probably already in good shape for buying a home.
Lastly, when you do go to buy a home the lender doesn't look at just one score, but typically 2-3 from multiple agencies. I thought my credit would get killed because I took out $30,000 at 0% on a credit card to invest it at 7-10% reliably, and though my Equifax score dropped almost 70 points for that stunt, the other two credit agencies didn't penalize me much at all so just last week I just closed on a $500 down 1st mortgage at the best available rates.