10yr residency-Dependants' visa expiring before 6 mths wait

Hi all,

Let me thank in advance for anyone who would take their time to help me out.

I am currently on the first three years of a Tier 2 General visa, which expires on December 2014. I first came to the UK in August 2004, so will be eligible (I think) to apply for the 10 year long residency in August this year.

I got married in 2008 and my wife came to the UK in the same year and have been living with me ever since on dependent visas. We also now have a little two year old, so both my wife and son are currently on dependent visas under my Tier 2 General visa, which also expires in Dec 2014.

So I am at the moment considering what our options are. If I apply for a 10 year long residency in August and hopefully get it - I think that would invalidate my wife and son's visas as dependents of Tier 2 General.

So is there a visa they can apply for along with my 10 year long residence application?

I read on these forums that they might be able to apply as dependents of a settled person (FLR(M)? ), if and when I get my 10 year long residence approved. However I am worried about that 6 months waiting time, which could mean by the time the decision for my application come back my wife and son's current visas would have expired (Dec 2014). Does this mean they would have to leave the UK in Dec, wait for my application's decision, and then apply from outside UK? Is that even possible with the FLR(M) application?

Or is there any other way that they can apply as my dependents without leaving the UK?

Any help would be greatly appreciated. Thanks all!