I've been looking for a forum like this for help for a long time - I'm glad I finally found it. I hope someone might be able to help me out.

I want to rebuild the interior mechanics of my very old (1988 or so) Jacuzzi brand spa to bring it up to date with a new efficient pump, new filter and an ozonator. I'd like to try and do this myself, but I want to make sure and buy the right equipment. The spa holds about 450 gallons with nine jets. The jets have been recently changed to modern "spinner" style jets and all hoses to the jets replaced. All piping is 2" PVC and flexhose. Here's the equipment in the spa currently:
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A Franklin Electric pump motor dated 1987 (!). It's a 2 speed 115v unit. The label says the horsepower is "1 - 1/8". I don't know if that means 1 hp for the high speed and 1/8 hp for the low speed or if the thing is 1 1/8 hp. The wires are only hooked up to the high speed so the low speed isn't being used. Other key info on the motor label is RPM: 3450 - 1725; FLA (whatever that is): 11.6 - 2.5.

A Martec cartridge-style filter with a 28 sq ft filtration area.

A Telstar TGS-50 natural gas heater with electronic ignition.

A Class Act brand timer and air button activated switch (first press - jets; second press - air bubbles - third press - both jets & bubbles; fourth press - OFF)
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I need to replace the pump to an energy efficient and quiet pump. I'd like it to be slightly more powerful than the current pump as the jets are very weak. I don't know if this is due to the pump just being old, inadequate or something else (perhaps build-up of minerals inside the heater element?) - Should I get one with more horsepower or are newer ones more efficient water movers?

I need to replace the filter - Should I get a larger (i.e. 50 sq ft) one?

Ideally I'd like to replace the switch/timer mechanism to allow for an ozonator and two speed operation of the pump (low speed for the timer daily filter cycle; high speed when it's being used). Most of what I see on this website and others are "all in one" units that will do all of this, but include an electric heater. I don't know if I should just get rid of the gas heater altogether (it's 16 years old, it works but I don't know for how long). Are the new electric heaters more efficient so the advantage of gas over electric not a big deal anymore?

Although not a necessity, I'd also like to replace the current switching control with one that is the newer touch pad style with perhaps thermostat control (however the later would probably need me to convert to a new integrated heater).

Any help would be greatly appreciated. If you've only changed out one of the items I'm looking to replace, feel free to give me your experience on that part only. Any bit of info would be great. Thanks in advance.

I want to do the same to my older Jacuzzi it's a corsica. It sounds like we have almost the same setup 2 pumps both 240v 1 is a circulating pump the other is the jets pump. my question after reading all the replies to this post is there a particular pack you would go with and why, also what jets would you put in the spa and why. what is the difference between the types of jets. I would appreciate any comments or suggestions.
Thanks
Bob