The kombi gear is great, top notch as usual for Stihl.
I got a power unit and long reach hedge trimmer attachment initially and then added an extension pole to make it even longer (!), strimmer, cultivator, and brush (yep, really, surprisingly useful !) later as needed. If I hadn't already got a long reach chainsaw and blower I would have got those attachments too.
It's a really good, pro standard system rather than a cheap lightweight diy setup and performs effectively and reliably.
Couple of things I would mention though, I bought the most powerful engine unit (130 or something similar ?) thinking I didn't want to get caught out with not being able to deal with some tasks, but there is a significant weight penalty that comes with that unit so even using the harness your arms and shoulders know when you've been using it for a couple of hours ! It uses a fair amount of fuel too. Buying again I would probably go for a mid range engine unit and save some weight and fuel.
I think Stihl only sell direct for collection from their dealers ? That's what I found in the past, so you couldn't just order on the internet from the cheapest place and have it shipped to you ? Don't know if that's still the case ?
Cheers, Paul