It will take time to get build your credit score. It isn't a race, it takes lots of patience.
Assuming you are approved for the Cap1 card, you will have two credit cards. I would plan for a total of three credit cards. As a previous poster said, the BoA secured card is a good card to go for. BoA is good about unsecuring the cards after a year or so. But I would check my credit reports to make sure there are no negative items before applying.
You could also think about a secured credit card from SDFCU. Thery don't HP for the secured card and there are no fees, but it will never unsecure. Your money will be locked up until you close the card.
You could also might be able to get a store card using the shopping card trick. It doesn't cost you a HP. Lenders may not consider store cards as highly as bank credit cards, but they are fine for your third credit card.
Since you don't have an installment loan and want a mortgage, I would open a shared secured installment loan. Here is a thread with more details:
http://ficoforums.myfico.com/t5/Understanding-FICO-Scoring/penalized-for-not-having-installment-loan...
Lastly, if you have a family member or spouse with a good credit card account (e.g. 10+ years old, perfect payment history, low util), ask to see if they are willing to add you on as an authorized user. It doesn't substitute for building your own credit file. However, it can help your FICO 04/98 scores.
