Hi Andy in 2006 after 25 years in the same job I decided it was time to give it all up & go travelling. Went through Asia, the Far East, Australia, New Zealand, the Pacific Isles, The States & Canada for the best part of a year. Where to go is really determined by your budget & where you want to go.
Your itinerary is pretty big to cover in 6-8 months. I spent best part of 6 months in Oz & NZ & still felt I needed more time there. If your intinery is determined by your wishlist of places you'd like to go on holiday to then you maybe best booking lots of seperate trips during that period & JY cover a lot of the destinations. Extended travel or a gap year is totally different, it is adventure & expolration & requires a somewhat different mind set to a normal holiday.
the advice I would give you in no particular order is;
1 I spent about 18 months before I left planning my trip so I could get the most out of it so use the internet, library & lonely planet books to help.
2, You'll need a Round the World air ticket. It goes in one direction either East to West or West to East depending on which way round the world you want to go. It's cost is determined by how many flight miles you do & how many stops you want. You don't need to fly in & out of the same airport in each country so you can travel around. Go to a specialist firm. I used Travelbag who were excellent.
3, Think about what the seasons will be in each country/ continnent you want to visit.
4, Think about your accomodation. I used a lot of hostels especially in Oz & NZ as they are cheaper & you get to meet people. My budget did allow me to have my own room rather than share a dorm.
5 You will need to manage your finances abroad & if you can get one get a debit card which doesn't charge every time you use an ATM. I kept moving money from a svings account into my current account when it needed topping up.
6, Travel light you will do a lot of clothes washing !! Get a decent travel bag or backpack it has to be bulit to last a lot of travel. Go to somewhere like Blacks for advice.
7, Get a decent diary to keep a daily journal of your adventure. I still enjoy reading it & reminiscing. Also get someone to save your ;postcards to create a scrapbook if you want.
8, Be prepared to be flexible in your travel plans both before & during. Your dates of departure from each country will be fixed on ther ROW ticket although for a fee you can change dates on route but be prepared to go with the flow when in the country itself.
9, Some serious stuff to consider. Make sure your will is up to date & you have set up an enduring power of attorney. Get the proper travel insurance for this type of trip. If your property is going to unoccupied during the trip get someone to check it regularly & get the Post office to redirect your mail to a family member or friend. Check your household insurance cover. Most policies have an unoccpuancy clause that will kick in after a set number of days & certain risks won't then be covered.
I hope some of this helps. A trip like this is what you make. For me it was a great experience & one I have absolutely no regrets about doing. My wanderlust is not yet exhausted either. I have a dream to spend about 6 months exploring South America in about 3 or 4 years time although I will definitely learn to speak Spanish before that.
My final piece of advice would be if you want to do & have the opportunity then just go for it.
If there are any other questions you've got let me know & I'll do my best to reply.
Good luck with your venture/adventure if you do go for it.
Keith.