Malaysia - any advice welcome

[MonsterMunchMe]

DP and myself are planning a two week long trip to Malaysia at the end of October.

Planning on doing a KL, Penang, a rainforest trek and ending it on a nice beach resort.

Any suggestions on the last two would be great!

Also it's a Muslim country so what is appropriate to wear?

I know it's quite rainy and warm in October, so long linen trousers/long sleeve tops? Do they need to be baggy or is it more relaxed? Also in the beach resorts are bikinis ok on the beach?

TIA

Just got back from Penang, we loved it! We got to go to Bukit mehra orang utan island which was nice but i actually liked Georgetown most of all, what a beautiful and historic place!
The hawker market in batu ferringhi was fantastic as well! Really great family holiday. But it's HOT and the mosquitoes were after us!

Malaysia is fantastic but I'm not sure Sipadan is advisable right now FCO

We loved the Perenthian Islands - more low key and basic than Langkawi. Just gorgeous.

Langkawi over Penang for sure. Langkawi has load of interesting things. A huge cable car, 7 wells waterfall. I am biased, I am no a huge fan of Penang but I live in Singapore so I didn't want the tourist thing.
I've stayed in Berjaya in Langkawi many times, it has the beach, the rainforest, the monkeys and a very laid back feel to it.

PSA - do not feed the monkeys. I left some hand lotion, some orange skins and the remains of a Pot Noodle on the balcony and was inundated with them. One female did have lovely soft hands though

Pangkor Island (boat from Lumut) - Tiger Rock - small eco guesthouse with fabulous food and jungle walk if you want it. Something very different.
Pangkor Laut - google the hotel there, there is only one hotel but the last time I looked on Tripadvisor there were very mixed reviews.
Or Air Asia to Borneo - Sandakan for Orangutans and hatching turtles on an island by boat.
E & O in Penang, old colonial hotel, near to restaurants rather than the other large ones on the beach.