It's difficult to say without knowing personal details of your situation. However, as a general rule, I would advise that a reverse mortgage may not be your best option, and probably the worst option to borrow funds for just a year or so.
First, reverse mortgages come with additional fees not found with other mortgages. Your FHA insurance premium will be 2% of the loan amount. You will also pay a servicing fee to the bank that can run several thousand dollars depending upon the loan amount. Bottom line: reverse mortgages are among the most expensive in closing costs. The shorter the term you hold the reverse mortgage the greater will be the cost of funds you borrowed.
Second, HUD just announced yesterday guidance to lenders on the new reverse mortgage purchase loan. Lenders will soon offer the new loan to customers. Essentially, you may use a reverse mortgage to purchase the home, but you will be required to make a down payment from your own funds (cash on hand or proceeds from the sale of your current home) equal to the difference between the amount of reverse mortgage you would qualify for on the new home and the purchase price. The down payment will be substantial, but if you qualify now for a reverse mortgage, using a reverse mortgage to buy your next home might be a better choice. Again, the costs of a reverse mortgage run significantly higher thana regular foward mortgage.
I recommend speaking with your bank about both options so you may obtain a precise estimate of your maximum claim amount, closing costs, and possibility of using the purchase option. Your bank may also suggest other, lower costs ways to finance your next purchase.
About 20% of the loans I write are reverse mortgages. Generally, I find about 2 out of 3 prospective customers would be better served by something other than a reverse (which means I'm referring them back to their banks). The closing costs (even with my el cheapo fee), negative amortization, and other concerns mean that reverse mortgages aren't for everyone... despite the fact that Robert Wagner is pitching them fast and earnestly on TV with the mansion and Jaguar in the background.
Note: HUD permits banks to charge up to 2% of your home's value as their fee. There is much, much less underwriting work in a reverse mortgage than a forward mortgage. Banks are collecting such enormous fees relative to the amount of work performed that HUD had to revise their rules to cap the fee. If you decide that a reverse mortgage is best for you... negotiate that fee aggressively.