Hello all, I just completed my CPL not long ago, and I planning to get my instrument and instructor rating as well.
Due to some family issues, I hope I can get them done by the end of the year.
Do you guys think it is doable if I plan to do them both at the same time?
Or I should concentrate on finishing one first then proceed to the next?

My opinion, FWIW, would be to do one at a time. Looking back, my 1st IFR was a bit of a struggle - lots of new stuff to learn and think of, and all the while still using a fair amount of CPU time just to keep 'er straight and level. After a year and a half instructing, and then 6 months on a 185, my renewal was a snap, as flying the plane came naturally. Now, that was back in the 90's, and there was no particular rush on to get into 'Air WestJazzWing', but I'd still consider - if you are thinking of becoming an instructor - getting your Class 4/3 first, flying for a while, and then going to get your MIFR...

There should be no problem to do them individually by the end of the year. You can do an IFR quite easily in a couple weeks. My friend did an instructor rating a couple years ago in 3 weeks. 5.5 months for both should be a breeze.

I would suggest doing your Instructor Rating first. This should really get your stick and rudder skills to a high level, which will make the IFR easier. Personally I would wait until you have a couple of hundred hours instruction under your belt before doing the IFR rating. That is what I did and I found it the easiest rating I ever did. Because I was teaching nav aids I had their operation down cold and solid basic flying skills meant I could devote most of my brain power to thinking through the procedures, not just keeping the airplane upright and pointed in the right direction.

The result was I only paid for 11.0 hrs of dual in the plane including the ride.

If you are just looking at yourself, first instructor and then IR will probably be easiest.

However, I think you'd be a much better instructor if you did the IR first. For one you'll understand nav aids better (hopefully) and you'll be able to fly smoother and more precise. That would benefit you even during VFR flying.

I don't see any advantage in doing both ratings at the same time.