is this realisticly possible?

hey im alex and im 19 from england, i am currently saving to travel se asia . I am planning to leave on a budget of £5000 .
Ideally what i would like to do is to fly into thailand and then backpack south through malaysia, indonesia and island hop across until i hit fiji, assuming allmost all my money has gone by now i will then go to australia and work there whilst trying to travel around oz and see a fair bit of the country.
Is this budget realistic ? i do like to go out and party etc but i will not go out every night if staying in means that i can travel for alot longer.

I plan to leave in 3-4 months.

Thanks

You dont say how long the money should last, but I can tell you that if you watch your p[ennies, it will last a long time in SEAsia on the backpack trail, and also can last a while in Fiji. Working in Australia shouldnt be hard either - there is a shortage of labour all over.

Sounds quite feasible to me. 5000 pounds will go along way in SE Asia.

It is a long way from Thailand to Fiji though, but seems quite doable to me, as the poster above says especially if you work in AUS on the way across to Fiji.

The island hopping idea works as far as Solomon Islands (you can get to Papua New Guinea from Indonesia overland through West Papua, and from Bougainville (PNG) to the Western Province of Solomon Islands by boat. However, while there are internal inter-island boats in each of the Pacific countries, beyond Solomon islands you will have to fly between countries, unless you find a friendly yachtie.
You will be travelling in the best season for yachts. If this idea interests you, once you get to Honiara, you can visit the Point Cruz Yacht Club (on the shore in the middle of town) and see if anyone is heading your way.

I should have added to the above, you can fly quite easily from any of these countries to Australia. However, you can''t work in Australia without citizenship or a working holiday Visa.

"you can''t work in Australia without citizenship or a working holiday Visa"
you mean you cant LEGALLY work

Any ideas what's the cheapest realistic way to get from Columbo (Sri Lanka) to S Pacific islands at the end of July/ beginning of August, aiming for the Cook Islands ultimately?

I've seen Columbo to Auckland flights for under £400, and Auckland to Nadi under £200, so this is a bit cheaper than starting again from the UK, and considerably less airmiles and CO2.

I should probably just google this myself, but how far do the catamarans between the islands go? E.g. can you go from Nadi right out to the Cooks (slowly and island by island is not a problem at all!).

You could look into flying from Sri Lanka to Fiji via Hong Kong.

There are no boats, slow or fast, from Fiji to the Cooks.
You must fly via Auckland.