I have had a YJ, then a CJ7, and now a CJ5
A CJ7 would probably be more practical for highway driving, and carrying family/gear
But in all honesty there are several things that would be more practical than either. A cherokee for 2k would probably be better suited, or a nice YJ (plus better mileage)
In your shoes I would probably keep the 5. More original, they are becoming alot more uncommon everywhere, and a nice looking one always gets a ton of looks.
They are very squirrely stock. I love that!
. I love that someone who has been driving around with me for a month can ask to test drive my jeep then pull over 30 seconds later and ask me how the **** I control that thing. Usually drivers alot more experienced than me too! (im 17) You can learn how to tame the beast, but it is not a general driving skill. I can keep mine in the lines on fairly curvy highways at 75 and I have a bent steering arm, but I usually use 1 hand (keeps me from overcorrecting too hard) and you really really really have to feather that steering wheel, you will get used the the balance after a couple hundred miles of highway.
As for speed, except for mileage I don't see a reason not to do a V8 swap in in any CJ. I have a 360 and I broke the 100mph barrier (101.3 according to my GPS) in mine on the way back from a camping trip today when some a-hole in an aerostar could not hold 35 uphill but because the passing lanes were all downhill he would stomp it and get it up to 80. I do not recommend this. Not only because it is criminal speed in AZ, but also because it can cause you to dirty your pants.
Reliability, (this goes for all CJs) I paid a well trusted family mechanic $800 to install the transmission I bought and go through and freshen everything else up. To date I have gone 8000 miles without having to put a nickel into it besides basic maintaining. But I also don't beat it too hard offroad, its my DD. It was not a bad price to pay to not have to worry about it leaving me stranded. I actually towed my buddies YJ 40 miles after he blew his Dana 35 on the trail. This is after he kept telling me how a CJ is going to leave me stranded when I was selling my YJ.
Honestly I think it will be a while before CJ7s really fade away but the 5s are leaving us quickly so I would hold onto the ones you have.