I know mist big box shops only allow you to go so low anyway, so most won't allow it..

I am currently shopping the market trying to find a primary residence that is a great deal for when I become stationed at Goodfellow, AFB. 

Now, I've only been in "the game" for a few months, and have nothing more to show than some book smarts and a lot of "no's" from the leads I've come across.

If I buy the materials I can comparison shop the labor on price/skill.

Your time here will be well spent.Your profile is empty and there is no mention of a specific REI area of interest, so, I added the below links from three of the most popular niches for your selection of one or all.https://www.biggerpockets.com/renewsblog/2015/01/31/ultimate-beginners-guide-real-estate-wholesaling-2/ (Ultimate beginners guide to wholesaling)http://www.biggerpockets.com/renewsblog/2014/01/07/flipping-houses/ (step by step guide to flips) http://www.biggerpockets.com/renewsblog/2013/02/22/buying-rental-property/ (how to buy a rental property)Now that you have made the move, below are some links that will help with the navigation of the site. http://www.biggerpockets.com/startherehttp://www.biggerpockets.com/meethttps://www.biggerpockets.com/alertsHow to Use @Mentions on BiggerPocketshttps://www.biggerpockets.com/ruleshttps://www.biggerpockets.com/termshttps://www.biggerpockets.com/inviteshttps://www.biggerpockets.com/perkshttps://www.biggerpockets.com/forums/categorieshttps://www.biggerpockets.com/courses/a-beginners-introduction-to-real-estate-investing (video courses)https://www.biggerpockets.com/real-estate-investing (Ultimate beginner's guide to REI)Before your 1st purchase, please ensure you visit the below link for some tips.https://www.biggerpockets.com/renewsblog/2014/12/19/real-estate-investing-success-smart-tips/REI books suggested by BPershttps://www.biggerpockets.com/renewsblog/2015/11/13/7-real-estate-books-beginner-investors/(7 absolute must read books for beginner REIs)http://www.biggerpockets.com/renewsblog/2013/04/14/best-real-estate-books/?

They are a broker and will shop all insurance. 

When financing a purchase for 'buy and hold' SFR what interest rate should I be looking for when shopping for financing options?

I would recommend staying away from the one-stop shop (rehabbers / property mangers) as they are usually more interested in selling homes than managing them. 

Ask them to pay an application fee and screen them through smart moves by transunion .

You may have more luck with the smaller one-man type shops than the big ones that have a dozen techs and a nice office.Depending on what kind of furnace you have now, and how much room there is, you might be able to leave the old furnace right where it is.