I'll cosign @Andrew Steffens  number though and I have ran furnishings either between $15-20 per square foot as a really rough ball park depending on location/style. 

Is there a particular architectural style of house you prefer? 

Since it's your first investment property, it can be a double edged sword since yes a PM can help you and be an expert voice but but if you don't know what you need or your management style yet, it might also not benefit you.Honestly, I'd try managing on your own for a while, and look up property managers in the area while you're at it.

Some indication or analysis of STR market suitability for investment - returns driven by cash flow market or appreciation. 

My wife and I opened a Chicago Style hot dog cart, and I reprised my handyman business I started prior to COVID.

Purchase price: $122,000 Cash invested: $31,000 *UK HOUSE* Purchased a 3 Bed 2 Bathroom Town House Style House in the UK from sellers who inherited the property, worked a very good purchase price in terms of value.

This would seem like a Section 8 style rental with no background check and a high risk tenant pool.

This is what I could find out from its listing:Type & styleHome type: SingleFamilyArchitectural style: Cabin,Log,Chalet,TraditionalProperty subtype: Residential, Cabin, Single Family ResidenceMaterialsStucco, Log, Block, Frame, Brick

@Adrian N.A LLC that holds rental properties is not suitable as an employer for a Solo 401(k) plan. 

Yes, Real Estate broker in the UK, and lender who specialized in buy-to-let (investor style) loans