Looking at your spec's the .2 to .25 thick limit's your choices if you don't want a 3/16h or .1875 thick blade .... the best of those available I think is the Basic 5 .... it is .25 thick and actually will feel lighter than the Boss Street .... it has a 5 inch blade and very comfortable Res C grip .... the tang is still a full tang and is as tough a knife as any other Busse or any knife made for the same size and thickness .... it comes with a great Asymetrical edge which is ideal if you are right handed .... it is convex one side and flat ground on the other .... very good cutting ability .... better than fully convex IMO .... but these knives very rarely come up and are hard to find ....
Another alternative is the BATAC LE or SE editions which are .25 thick .... they also have 5 inch blades .... but the handle is much larger than the Basic 5 and the balance point is way back in the grip .... some like that .... I personally prefer a slight blade heavy bias .... I had an LE and moved it on .... the normal BATAC's are .1875 thick and IMO are the better for it ... because the weight overall seems to offer better feel and control .... the SAR4 is another good choice at .20 thick and as said has nearly a 5 inch blade .... again though I had one and felt the handle slightly too heavy compared to the blade .... but as I say .... that is just a personal preference ....
The S5LE is done by Scrapyard Knives and is in Infi .... it comes in at .1875 thick with a full tang and is easier to find than the Basic 5 ... that is a great choice and IMO you will never break Infi in a shart blade like that so the slightly less thicker stock is not a worry IMO .... and if you do you will be covered by the lifetime guarantee ..... but no-one ever has ... this is another great knife for comfort, light weight and good balance .... it is the bottom one in the pic below ....
It is however a sabre grind but it is done well and I can do everything with this knife that I can do with the Basic 5 ...
Again if you don't mind a perfect balanced sabre grind blade .... the RMD in SR101 steel is an excellent 5 inch blade .... one of the very best knives in this size range IMO .... and again it is .1875 thick stock ....
These are the ones I have kept anyway as I like a knife in the same size range and spec's as yourself ... and I have tried all of the above.
Of the ones I have'nt tried .... the HG55 LE is a nice choice in a 5 inch blade and is .25 thick .... they too are easier to find than a Basic 5 .... and it is a flat grind ....
Let us know which one you go for ... :thumbup: