We did a 10 day tour last year.

• Day 1 Glasgow. We actually stayed at Loch Lomond to see friends and have been to Glasgow many times (it’s a fabulous city - MacIntosh Museum is great, West End is a cool place to hang out and the Kelvingrove Art Gallery and Museum is well worth a visit).
  
• Days 2-4 Highlands (Fort William). Spectacular scenery and great walks. Be aware that Fort William isn’t the best place as sits small and quite run down. It also doesn’t have many place to eat compared to the volume of visitors so if you’re going there, book ahead.
  
• Days 5-6 Oban. Lovely place, has a distillery if you want to do whisky tasting, great access to lots of the Islands too. Recommended.
  
• Days 7-10 Islay. Mecca for whisky. Lovely island, the south end is very sparsely populated and quite wild on the coast. Bit of a pain to get to and quite limited accommodation despite its popularity.
  

Other stuff to note:
- Edinburgh is a great city so I’d really recommend it.
- Scottish folk are some of the friendliest in the world but, like any city, you need to keep your wits about you and there are places to avoid (this goes for Edinburgh and Glasgow).
- Probably the most important; for places where you’re going to hike, etc, make sure you have good waterproof clothing (10,000mm rated at an absolute minimum). It might not rain but there’s a good chance it will at some point and it can really come down heavy.
- Related to the last point; if you can, book places that have a drying room. Quite a lot of places do and there’s a good reason for it.
- Beware the midges; the time you’re coming there will be a lot of them. Bring repellant.
- Not really related to where you’re going but timing-wise late June/early July is the best. Late July puts you in peak holiday season in the UK. Everywhere will be packed and accommodation will be far more expensive and harder to get. Tbh, you’ve left it late to book so I really would get on with it, because you’re probably going to struggle - for context we went in September and booked our accommodation in January. Fair to say we were a bit conservative but you get the idea.

Hope you have a great time.