It's a shame Kenne Bell no longer makes a supercharger for these vehicles

Well, the 5.9L that is!
One thing to remember with any major engine build is you get what you pay for in almost all cases. If cost is an issue, check around online for used kits that people take off before selling/trading in their vehicle. Rushing into a build on a budget is a bad way to start. A full turbo kit with intercooler (and perhaps a warranty) will run at least $3K, if you choose not to install it yourself, add on another $2K in labour.
Most stock engines can't handle more than 5psi boost without requiring upgraded internals and gaskets. A good 'kit' can put out 10-12psi, however once you factor in upgrading the engine to handle the boost you'll soon start to seep into the five figure mark.
I have a '99 Civic Si as a weekend toy and it's stock with 308,000kms (nearly 200K miles) and I decided to bite it and check out one of their 'meets'. A guy with a base 2002 hooked up a gas blower to shoot more air into the engine. However, he failed to realize that adding air alone won't do anything unless you add more fuel to compensate. It was rather hilarious to say the least and it's good that you posted here to see what is viable for you. But, only YOU can decide if a turbo is the route you want to take.
The 4.7L can be cammed and there are tons of bolt on mods that with even an SCT tune can get you an extra 30-40hp from your 4.7L. These mods will run close to $3K to get that HP if you do the install work. It'll be nearly as much HP as you'll get from a basic turbo kit without the hassles of digging deep into the engine. However, it's your vehicle and your choice! Happy modding....