Buying a new build - debate on deals

Hi,

Bit of advice if someone can please. We have a mortgage-free property that we want to sell and buy a much bigger new build home. Obviously, we're aware we can sell up and buy the new home, go with an Easymover kind of scheme or part-ex. What I'm not getting a clear picture on is what the best option is. Any opinions?

I'm worried that if we start to sell independently as you normally would, and our new build home is finished before we sell, we run the risk of not completing and losing out (both on getting the plot we want and on the fees paid to reserve). Anyone been through this before? I'm not quite sure how a chain works in a new build - I'm getting the feeling the developer won't hang about forever waiting for you to sell your home...

Easymover seems similar but with them involved and supporting you in selling independently.

Then there's the part-ex option. I know they're likely to offer slightly below asking price, but the developer we're talking to has said "there's always a deal to be done" and may be able to do us some cashback towards stamp duty/flooring/upgrades to make up for the shortfall in the valuation on our current home. This does seem to take the hassle out of it all, as they'll allow us to stay in the current home until the new one is completed, then it all goes through on the same day. BUT this does seem too good to be true.

Anyone with any experience of this??

Thanks in advance

Debbie