here's the thing...
You're looking for a 90% Loan versus a value at 165k, right there you are going to be in a higher interest rate range. Remember interest rate = RISK... The higher the risk to the lender, the higher the interest rate is going to be. 2nd you state that you have "Less than perfect credit", that is another hit to the interest rate.
In cases like this, I most often find it beneficial to actually HELP people understand thier best path. Now, you've been paying on the two mortgages for several months I'm sure, being as you have a 2nd mortgage that is comparable in size to the first, so what's the rush???
You should find a professional who has been in the business for several years and can help direct you in the most financially beneficial direction. Personally, I would work with you on your credit for a month or two and get your scores up. Have you had any lates to the mortgage? If so, when? What other late payments have been made and when? What is your primary source of income? how long have you been on your job? Do you plan to move within the next few years? how old are you? do you have a retirement plan set up? when do you want to retire? I already know you don't have significant savings and that is a concern to you, how can we work together to tackle that issue? What type of lifestyle do you lead/what's important to you? do you have children? what are thier ages? Finally, what is the market like in your area? Are values increasing/decreasing/holding steady???
All these questions are a major concern to you at this point. The only reason I go through all this is so you can see that there is more to it than the simple "What's the best bank for a refinance for a person in my position?". The question should be, "Who knows what they are talking about and isn't just some kid sitting behind a telephone looking to make a quick commission?" Trust me, I used to be that kid until I found out that I wasn't going to be in this job for long if I didn't start liking what I was doing.
Find a reputable mortgage broker, one who wants to assist you financially, not just help himself financially. Stay away from large mortgage companies at this point.
How do you know the broker is reputable? Well, he'll ask you all those questions I just aked. If you want to talk further email me, I won't even ask for your business :)