Bringing my girl into the 21st century

I have an all original 1986 Mazda B2000 LX Cab Plus (Black and Silver). The engine is the 1998cc 2.0 liter 4 cylinder with carb and a manual 5 speed transmission. I believe she originally had about 98HP and 120 pounds of torque. I worked all through high school, saving every penny (missing out on trips with my friends and parties) so i could buy this truck. Had her ever since. Brought my kids home from the hospital when they were born so a lot of sentimental value with her.She still runs but I want to begin a restore. My plan is to make her look on the surface and interior exactly as she did new but under the skin, bring her to the 21st century.
Upgraded suspension, wheels, tires, exhaust, clutch, drive train.. etc. I want to the keep the numbers matching block with the truck but I would like to see what I can do for improved horsepower. This is where I need your help and expertise. If I improve my clutch, drive train, brakes exhaust to accommodate the increased power, what do you believe is a reasonable goal for power? I would prefer 150-200 HP without adding a turbo etc. The goal is to have a truck that still remains tame and a great cruiser but at the same time has great handling and performance for the occasional spirited drive. I am not sure if that target power is reasonable and if not what do you think is while meeting the requirement of my stated goal.

Also if there are things that you recommend for rear end changes etc please include. Just looking for a road map and what you think is realistic considering I want to keep everything original looking.

Most people who want more power than the stock 80ish just do an engine swap. From what I've read it's hard to make more power out of these engines without dumping tons of money in it and turbo.. Maybe someone can shed some light on this if they've tried to get more power out of the stock engine

I think you're barking up the wrong tree.

Me? How so?

Simplest upgrade> v-6 of your choice for drop in fit [I did 4.3 Vortec GM with carb (pre '84) and '86 HEI distributor (no bot)], no truck modifications, instant double horsepower.