Wrong forum Buying investment prop(to let out)

Am buying a second property for 250k as investment.Have 84k tracker loan on principal residence(worth 750k plus).have 50k savings to put into inv property.Current lender wont do new loan so any advice on what is best way to go to secure lowest intersest rates(against main house if possible).Income is solid.Total new loan =84K+200k=284k.
Thanks