Susan,
I'd suggest that you look at taking a $417,000 first mortgage to get conforming rates rather than jumbo rates. (over 1% lower)
For the balance, we'd have to find a lender/bank willing to do a home equity line of credit for the balance that you need. I also live in Downtown Denver (Glass House).
Please feel free to call me at (314) 640-3300.
David Robnett, CMC, CRMS
LeaderOne Financial