what is your thoughts on old houses built in 1950/60 but remodeled like new?

This doesn't cost you anything other than a few minutes of your time... and they will likely be able to give you a good estimate based on the location, the year the property was built, the type of construction, etc.

In Tampa Bay, our prices are increasing rapidly. 

There is a steady amount of new homes being built in the suburbs.

Bathroom hardward (TP and towel racks) - mount to a 1x4 plaque that is screwed to studs. you can pretty much hang on it without pulling out the hardware. i use entry level granite countertops - stain resistant, and should last a long time. i put LVP through the entire house, bathrooms and closets included. its water proof and scratch resistant. while the initial cost is more than carpet, you wont have to replace it as often. i use Sherwin-Williams Harmony line of paint, in a semi-gloss sheen. the semi-gloss is easier to wipe off for small marks, and the harmony line has deodorizers built in. for exterior door knobs, i use the smartkey knobs from kwikset. you can rekey a knob in a few minutes - no need to pay rekeying fees anymore. last tip - figure out which appliances your market typically provides. in my market, its not common to provide washers and dryers, so i dont. thats one less thing to have to repair. 4. i dont see an issue with the gas stove. to convert to electric you will need to have a 220V plug, which could be costly to install if not already there. 

Any idea of the rent ranges say on a very nice 4/5 br 3 bth built 2000 on large lot?

If I do end up investing in my current location I will have built up a solid team and network of investors.

A builder is building houses in a new neighborhood and it looks like they currently have houses built waiting to be sold, some of which have been on the MLS for 30+ days.

Since there doesn't seem to be any modern small multifamily available, I've thought maybe I should have it built.

You'd be hard pressed finding a rental built after 1910.