I was going to go without a red dot on my tantal and just save up and get a SGL-31 with a russian red dot.  This is not that financially feasible anymore.  

So I was thinking of things I could do to my Tantal. I plan on getting a Vortex SPARC for a red dot.  Now what are my mounting options?

I like the looks of the Dog Leg rail system.  I am having doubts about the ultimak rail system... plus does that even work on a Tantal?

What are some other options?

I've had both (Dogleg first then Ultimak because I didn't want to do the permanent cutting of the top portion of the handguard retainer).  After waiting 6 months for the proper 5.45 peep to be developed and reach my door I chose to switchover to the tried and true Ultimak.  There's no flex in the Ultimak and tons of people run them with red dots with heat being the only issue (buy a legitimate optic and it won't be an issue).  The only reason I'd say to use a dogleg is if you need the optic to be closer to your eyes for the proper eye relief otherwise the Ultimak is cheaper, less flexible, and you can actually co-witness your sights.  And yes you can put either on a Tantal as shown below.
Before


After

what do you mean by flex in the dog leg rail?

Due to the length and thinness of the dogleg there is actual flex in it when you push and pull it vertically.  There seems to be adequate return to zero for everyone in the primary dogleg thread, but I wanted more peace of mind.

What safety selector are you using? How do you like it compared to one of the Krebs style ones?

That is a standard Tantal selector and it won't work as a safety selector on a semi unless modified.

huh... mine does

Yeah it works fine as a safety selector on my tantal, but since it's so small it's tough to get enough leverage to shift the gun into fire with it.

I am sorry, I was thinking of the rifles built on a standard AK74 type receiver, not the one made for the Tantal.