Mathematically, you should retire the highest-interest debt first. But let's consider some other ideas first:
1) Do you have enough home equity to potentially get a loan at an even lower interest rate? If you could consolidate one or both of these loans as a 2nd mortgage and reduce the interest rate, that would probably be the way to go, especially if your credit is good and you can get a low rate. Then make the minimum payments and invest like mad.
2) Depending on your level of risk aversion, there are investments that yield just over your loan rates. Examples: The preferred stock exchange traded fund PFF yields 5.75%, and is less volatile than the stock market. The Vanguard REIT fund VNQ yields 4.8%. You can find closed-ended funds on cefconnect.com that use leverage and discounts to squeeze higher yields out of bonds, such as BBN (taxable muni bonds) which yields 6.59%, or PCN (corporate bonds) which yields 8.88%. All of these are risk arbitration moves - you're borrowing and investing in something riskier than your loan. However, chances are good that you'd come out ahead by investing as much as possible in a portfolio such as this and making the minimum loan payments. Be warned that this strategy will feel like a loser if there is a correction.
Neither of these options meets your stated goal of being debt-free in 2 years, but I bet either one puts you ahead in terms of net worth. Be careful what you wish for. Two + years spent earning four percent and some change might not be the fastest way to FIRE.