If you consider bluenile before, then you can consider the below alternatives (all of them sell Super Ideals), all of them ship to Malaysia. You will have to pay 6% GST.

Affiliate links:
WhiteFlash: https://www.whiteflash.com?a_aid=myengringexp (free delivery, AGS cert)
Brian Gavin: http://www.briangavindiamonds.com/?a_aid=myengexp (no free delivery, but the diamonds are top-notch, AGS cert)

Non-affiliate link:
High Performance Diamond: http://highperformancediamonds.com/ (free delivery, AGS cert)
Jann Paul: http://www.jannpaul.com/ (not sure, but I think no free delivery, GIA cert)

As for setting a diamond, if you don't mind standard settings, I checked with shops like Diamond & Platinum/DeGem before (they belong to the same company anyway). Both of them will do setting for loose diamond. You can only choose selected designs though because certain designs are tied to certain diamond brands they carry, such as Estrella or Forevermark. Poh Kong and Tomei also will set loose stone as well.

The downside is that they probably won't be responsible if anything happened to your diamond during the setting process and the prices can be vary.

My advice is that if you find out the size of the wearer's finger, and then make it correct the first time. Subsequent resizing of the ring may affect the appearance of the ring more or less.

It is also advisable that that you make some effort to travel down south to KL/SG (Jann Paul) and get things done right. It is not a small purchase and whoever that receives it may feel touched for your effort.

However, if you manage to find any jewelers in Penang that can do customized ring setting, then feel free to share with us here. I am sure some of us will benefit from the info you share. Not all people stay in KL.

Let me know if you need further help with choosing diamonds.

Thanks. 

This diamond is slightly on the shallow side, with the wider table and slightly short crown height.

34 degree crown angle is an acceptable angle, but I would prefer something between 34.3 to 34.9 in order to get more fire. But this is just my personal preference, getting a 34.x degree crown angle is already something not that easy in the market. So I will consider this diamond one of the better ones.

I based this on AGA/NAJA cut class grader:
http://datlas.com/AGA_NAJA_Cut_Class_grader/index.php

Tab Percent: 1B
Crown Angle: 1A
Crown Height: 1B
Pavilion Depth: 1A
Girdle: 1A
Depth: 1A
Polish: 1A
Symmetry: 1A
TotalGrade: 1B

HCA is 1.4
Light Return: Excellent
Fire: Excellent
Scintillation: Very Good
Spread or diameter for weight: Very Good
Total Visual Performance 1.4 - Excellent within TIC  range

Enchanted Cut Score is 97.2%

Overall, I would say that this diamond is considered better than most you can find.

This diamond has been there since May 5, 2014. I would feel strange that it is still there, considering the proportions and price. My guess is that:
1. It is already preset in a ring setting and has been in the shelf since some time ago and now they are doing promotion to let go of this diamond ring. Correct me if I am wrong though.
2. The diamond doesn't look great when you look at it. Hence, it is not sold. Remember that good proportions does not translate to good performance because we do not know about the cut quality based on proportions alone.

However, I have to say the price seems fair enough, considering you are getting side stones on a 18k white gold (Is 18k right?)