"I think I'm going to take some advice, I think my next "guitar" will be a bass, Obviously, my choice will be a Fender bass and bass amp."
You've come to the perfect website.
The Fender Precision bass guitar has a deeper growl than any other bass guitar.
This amp looks interesting:

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you can save the world with your guitar one love song at a time it's just better, more fun, easier with a fender solid body electric guitar or electric bass guitar.

Hi SSP,you left out a Fender bass and the one that I would pick hands down and that's the Jaguar bass.Of all the basses it has the greatest tonal range and what's especially great about it is the super slim neck that makes the transition from playing guitar to bass a whole lot easier.When I saw the first one in my local music store I was drawn to it immediately and almost bought it,but was on a Strat hunt instead.

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'65 Strat,65 Mustang,65 Jaguar,4 more Strats,3 vintage Vox guitars,5 Vox amps,'69 Bassman with a '68 2-15 Bassman cab,36 guitars total-15asst'd amps total,2 vintage '60s Hammond organs & a myriad of effects-with a few rare vintage ones.

You'd get more out of a jazz bass, versatility wise. Plus jazzes typically have slimmer necks than precisions, which makes the switch from guitar easier.
I've recently added a push pull pot to my mexican jazz, which means I can make it produce a fairly convincing precision tone.

Of course all is subjective, and someone will come along with views completely antiphonal to mine, but none the less, listen to me.

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Rated "M" for meaty.

You mention Jazz and Precision as possible choices, the Precision may just be the standard for low end and the most popular. And the Jazz may be more versatile and has a slimmer neck, maybe a little lighter than the P bass.

But you mentioned the Mustang too, now I'm a huge fan of short scale basses (I have 3 of them myself) and I would definitely suggest you try one of these out. Shorter scale means not such a huge size difference from a guitar, lighter, IMO more comfortable to play. A Mustang just may fit into your stable easier if you've had nothing but 6 strings around.

Just my 2cents, but one downfall I will point out is that short scales typically suffer from "neck dive" based on the lighter body weights and standard size tuners, I have a Fender, a Squier and an SX and they all suffer from this.

I have a Line 6 amp which I love and have never owned a Fender bass amp so I can't comment on that.

'Stang:

My Mustang experience:
I tried to own a mustang and returned it.
The upper fret access is virtually impossible (for me) because the neck joins the body at a lower fret than a precision.
Mine had severe neck dive.
Also, my funny bone would be sore after playing. Just not a good fit for me.
Sounded great, though.

Jazz:
Haven't played a jazz enough to tell you anything about it. But they do have the narrower fboard at the nut.

Precision:
I have 2 precisions and they have always been fantastic playing, looking, and sounding. Better sounding than anything I have ever played to my ears.

You should definitely go to a shop and try all three if poss for best fit and sound for you.

Probably the best advice on here is "go to a shop and try them all if possible." I am pretty biased to short scale so I'm going the Mustang route. You couldn't get me to trade a short scale of mine for a P-bass, just like wearing a boat anchor for me.

To each his own, you might feel very differently then every one of us when it comes to what feels right.

My son prefers his Jazz Bass over the P-Bass or his Tele Bass. He refers to it as his "high performance" bass

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"Life is like eating jalapenos. What you do today may burn your arse tomorrow"