Thanks for all the replies guys. I suspected I would get disparate and conflicting replies. You have not let me down.
Docrwm - good point re the WR of the kit lens. I'm thinking it may get a gurnsey in a suitcase as a backup for my partners' non-wr 18-250. This looks to be a self sherpa trip though.
Tougefc- man you are way too minimilist.
I think I would have a form of buyers remorse if I left all those beautiful primes behind. I mean, why buy them if not to take them to the most picturesque places? I appreciate your line of thinking though, and it would certainly solve the weight connundrum. If I had your talent as a photographer it would make me more confident about a minimilist kit.
Lowell - I'm aiming to cover as many eventualities as possible. Street, landscape, architecture, portrait, etc. Given the nature of the trip and the places we are going, I think I want to have every potential subject covered. I'm not sure I will have safe storage 100% of the time. Certainly I should be ok in the better Hotels we have booked in Singapore, Penang, KL and Bangkok, but the Nepal leg is a pre-paid all inclusive type trip, where we have no control over the choice of hotel. In New Delhi, a brother in law of an Indian friend is arranging thing, so again we have little control over the quality of the hotel. I am a lot more confident than I am for Nepal though.
Yamakasi - thanks for chipping in. I may even PM you with a few questions about Singapore and places to shoot/see if you don't mind. I would love to be able to tag along on one of the Singapore Pentax group's get togethers. I don't think I mentioned we are getting the train from Singapore all the way to Bangkok, vial KL and Penang. Do you have any advice or experience for this trip?
Azzy - thanks for your contribution. I can and do fit all the lenses mentioned in one bag - a Lowepro slingshot A300. It gets a little heavy, so my usual method is to do as Lowell suggests and make a choice for the day out of the selection and leave the rest at 'base camp'. I'll ponder your suggestion about leaving the WA zoom behind. I may take it and the 15mm out for a landscape 'shootout' and see if I can live without the 12-15mm range.
Frogfish - thanks to you too - but...but ...I just bought the 60-250 and 100WR, can I possibly leave my newest 'toys' behind?? Not sure what you mean about plastic bags and rubber bands. My lenses all travel in their individual padded bags.
Rio - my friend for you I should have listed my classic manual focus lenses.
How about the beautiful tiny Takumar 200 F5.6 preset? A50-135? SMC 28 F2.8 etc. I'm not sure I have the vision or talent to limit myself to just four lenses, as practical and light weight as your suggestion is.
I mentioned the slingshot bag, but I'm thinking about buying a more knapsack type bag. The slingshot concept has its place, but from experience having all the weight on one shoulder can get tiring on a long days sight seeing.
Thanks a heap for your replies gents. You have given me a lot to think about.