Im not sure about the outlet but if you go to Seng Heng website, there's a lot of bashing that lots of the customer can't get their phone and a lot of bad reviews. I would avoid these reseller instead i'll walk in Apple authorised store to buy the phone.

You can try Shopee or Lazada with vouchers and so on. They also do have instalment plans available ready for you if you need it.

Plus, using MBB Amex on Shopee gives you 5% cb on weekends. That's an automatic RM50 "discount" already. + Shopee Coins of max RM30. You can do your math on both platforms. Sometimes but rarely, they do have discounts on NEW models but don't expect massive discount.

My iphone 8 plus is 3 years old now.

Using 64GB + 200GB icloud.
Internal storage 40GB/64GB only.

So far so good.

Your case, 128GB + 50GB icloud should be sufficient.

128gb is enough. Subscribe to iCloud.

For icloud, 50gb is rm3.90 a month.

256GB better.

128 gb is more than enough unless u're very into photos and videos

Why wah?

Convert your higher storage to icloud, then you will find icloud is more worthy.

If u use a lot apps, then 128GB + 200GB icloud / can start from 50GB initially

If not, then 64gb + 200gb icloud/50 gb icloud initially is an optional and save your money

So end up buying which one?

128gb is more than enough

Good choice , hopefully you buy blue like tru chads