Howdy Mr. Jonas,
I do not know if there are really any hard and fast rules on fps that clearly distinguished various levels of ammo, at least in my mind. But if you are talking about factory loaded ammo, I would think this might be some useful approximate figures.
With a 148 gr HBWC most will be loaded to what I would call target velocity. It depends on both the powder and amount of powder used, but think of target level loads as being in the 650 to 800 fps range.
With most factory 158 SWC type loads, you would probably find both a "target" and "duty" type loadings. The target rounds would be in the same neighborhood already stated, and the "duty" type loads would probably be in the 800 to 1000 fps range - again depending on the powder and amount used.
If a round starts to move above 1000 fps I tend to think of it as a "hot" or "hotter round", designed more for duty or self defense carry.
Since I do not know what brand and bullet weight of the JSP load you have access to, it is a bit difficult to offer strong suggestions. I personally would not feel underarmed with a 148 HBWC target load, if we are talking bedroom type distances of home defense usage. Nor would I have a problem using the 158 SWC in either the target of duty type levels. Since I would want to be using a speed loader for a reload if necessary, I would prefer the SWC bullet shape as it will load more quickly, especially with a speed loader, than will the HBWC design.
If the JSP is intended for defense use, I suspect it is either in the "duty" level or even the hot/hotter category. If I could not use a JHP round, I would probably want a JSP instead - if I had the choice.
But the bottom line to me, for bedroom type home defense situations, I think any of these rounds will do their part if I do mine. I think where you put the round on target is of more importance than what round you fired as long as the rounds are clearly not apples to oranges. If your options were a super slow target load or a super fast JSP, I would probably lean towards the JSP if I had that option.
Maybe you would like to try all of the availabe bullet styles in your pistol, and decide which load seems to suit you the best in your revolver.
Hope this helps a little but does not give you a "buy this one" answer. There are just too many unknowns for me on brand, bullet weight, power level, etc, for me to be able to do that intelligently.
twoguns