You can go to a bank/credit union, online, or to the dealer themselves.
A home Equity loan will use the house as collateral, an rv loan uses the rv itself as collateral and a personal loan has no collateral tied to it.
The rate is dependent on the lobby rate or prime rate with your credit score and worthiness factored in. 4 percent seems like a decent rate without knowing your situation.
Your home loan is not tax deductible (in a sense) the interest you pay on that loan is. An rv loan is not tax deductible neither is the interest (maybe if it is your primary residence - not sure on this one).
2015 Forest River EVO 2850
2012 Dodge Ram 2500 6.7 Cummins
Yamaha 2k x 2 with parallel cable
EMS 30 PI portable w/ Edison plug
Nights Camped (2016-13) (2015-13)