Bill, doesn't the 1999 L36 come mated to a 4T65 though, which woudl be Cody'* case?

YES. But there are other people interested in this topic. That statement isn't true in all cases.

Okay, I wanted to ask the gearheads.

Which one would pose the least risk of ruining my reliablity.

GT1 cam with all the necessary items (springs, etc) combined with a ported TB and INTENSE PCM
(This option is the most expensive since the installation is 600 bucks)
OR

Yella Terra 1.8 rockers with all necessary items plus HV3 and ported TB and INTENSE PCM
(This option is the cheapest and only requires tearing into the top end, not the internals)

Thoughts and advices would be appreciated.

Personally, if I were to rocker my N/A car I'd use the ER rockers coupled with the HV3 and PEM'*. I'd have to double check but I think they don't require new springs to use them, although it wouldn't be a bad idea to do them anyway.

I am running the ER rockers on stock springs. I have talked to zoom and he said stock springs are good until 6000 rpms.

This is also what I would do. (PEM'* being a powerlog and ported rear) Reliability should be the same as stock with this setup, stock valvesprings will be able to be used with no issues. The only other things I would consider is a 2.5" downpipe and a PCM.

All of that should wake your car up quite a bit, and probably actually increase your gas mileage, while being reliable as well.

that is pretty much the exact setup i have planned. ER rockers, p-log and ported rear, 2.5 off road downpipe, HVTB, HV3, and P&P LIM.

If you do decide to go cammed a standard Intense PCM won't keep it in tune. You could get a pcm from ZZP programmed for their cam or get a custom tune from Intense since thats where your getting it installed.
Go ERs like others were saying.
This will make a more reliable, less fussy combo. But, it will only yeild 1/2 or so of the hp of a cam though. If you really want to add power n/a then the cam is the way to go.
I mean, camming isn't going to be the reason for your car leaving you stranded or anything. It will just be more sensitive to weather changes and your timing chain/damper will wear a little bit quicker. If you install a new set anyway you will probably never have to worry about it agian.

What you mean? More senstive to weather, like how, will it be lame in hot weather and more peppy in cold weather? Or the opposite? And why?

It will feel more sluggish in hotter/more humid weather, yes. It will be more noticeable than with a stock cam and tune.
For instance, my summer tune was different than my winter tune.. The fuel trims would be off, i would adjust accordingly via afc, and it would be good for the season.
Keep in mind I was OBD 1.5 so this may not apply to you.
Your car won't be a dog when its hot/huimid but you'll be able to tell the difference.