There's plenty of Metz flashguns around at good prices. I bought a case full of Metz 45 CT battery packs and accessories about 18 months ago, there were about 25 battery packs for Metz 45 CT-1 to CT-4 flash guns, there 's a large power pack for a Metz 60 CT1-4 and a boxed battery. It had all come from a repair shop that had closed down, My older Metz unit is a 402 so pre CT series uses a power pack and the battery unscrews so I refurbished it with new NiCads after about 30 years use, it has the option of NiCAd or Lead acid batteries, but the Lead acid batteries don't last long.
I'd picked up a mint boxed 45 CT-1 at a flea market a few months earlier and then a few months ago a CT-1 and a CT-4 for £20 ($26) with no battery packs. Luckily about a dozen of the ones I'd acquired before were OK, and I have 4 chargers.
Now I have a cased portable flash set-up with spare batteries, I l also have two holders for regular AA rechargeable batteries, Sometimes I need to paint an interior or cavern with multiple flash exposures and assistance
In all honesty for normal use I've never had an issue with lack of power with the 402 and now 45 CT- or CT-4 even when used bounced off a ceiling and the Auto settings are spot on in terms of exposure. I prefer the flexibility of the 45 CT's not having the heavy power pack of the 402 or the 60 CT's.
Ian