Any suggestions would be whole heartedly appreciated.
Not unless the seller is dumb enough to take a second mortgage.
A HML will always take first position. Some will allow a second position including for a motivated seller who is willing to finance by taking a second position lien.
(There are exceptions but nowhere near the $ level you are operating on if you are asking such questions on BP).
In addition the vast majority of HMLs have minimum loan sizes. Usually $75K or even higher.
The way to consider doing this is a HML for the 1st position lien for the majority of the loan and the motivated seller taking second position and paying whatever the HML doesn't cover. Don't forget there are also loan costs either the seller has to cover or you do.