Yo? New here and New LS2 build "The Sleeper"-Need Advice

Hello from the Omaha, Ne area! I'm like most people with a certain level of fear of commitment and I have been siphoning a lot of information, enough to confuse me) so I have decided to join.

Here's what I have ...
2000 Chevy Silverado 2500 6.0 with 370,000 miles on it. I have called it an LS2 but I actually think it's a LQ4 since it's an iron block or so I've read on here. I've had the truck for 10 years and I paid $6500 for it in '08 when the economy tanked. Texas Truck so rust hasn't eaten it all up and it's my daily driver. I purchased a used engine, stock- rebuilt it, stock except for the fancy K&N Intake you can see in the pic. I have 50,000 on the rebuild with no issues except the usual Gm ones we all know about. Transmission shudders due to me bending the shaft pulling it out because I could not get to the torque convertor bolts when it locked up.

Here's where I sit ...
I refuse to pay 20k for truck with unknown issues so I finally decided I'd put 10-15k in mine and know what I have. I still have the engine in my garage I tore out (iron block 6.0)so I thought I'd build it with some zip.

Here's where I'd like to go ...
More HP and Torque... like everyone on this site I suppose. There is a ton of info and suppliers now a days. A lot more than when I'd look at the Haynes repair manual in the public library and make copies of it. I'd like to use the block I have. I do not mind spending extra money on good quality parts( I was recommended an ATI under drive balancer) but like most I do not like wasting money on brands and parts with no results.

Here's what I need advice and recommendations on ...
I have heard LS3/L92 heads are awesome -ported or not, intake, throttle body and size -92-102?, cam, valves springs, rocker arms, 1.7 or 1.8 -shaft or stud mounted, pistons and rods, push rods. Yes, it's a lot. I have read a lot also but there is so much, I wouldn't say conflicting information . . . but options. I like to talk to the guy/salesman that has been there, done that, and owns it for advice.

Once again it's a daily driver but I love to crank up the tunes, roll the windows down and punch it on a lonely stretch of road. I also love it when, at a stoplight, a punk kid yells out the window " Ya wanna race, old man" It's like I'm 87 instead of 47 - so yes, I like punch it then also so the kid can take the car back home to mom... defeated.

Thank you for having me and I also Thank You in advance for any and all advice on parts, suppliers and what has made your ride sing.
FYI -I have priced out a Monster Transmission and transfer case. If there are better and more cost effective set ups I am all ears. I should say eyes... I'm all eyes.

Thanks
Don