Since an interstate entails a longer travel it is more convenient to hire a removals company to help you. This would mean less worry during the travel. This is because you won't have to watch over other items. Your stopovers would be safer too.
Make sure that you hire a reputable removals company though. The company should be transparent when it comes the terms and conditions. You should be given of a copy of your rights and responsibilities. Of course, you should read it too so you would be guided during the move and in cases of disputes.
You should know the costs though. Interstate moves are charged according to the weight and distance. To get a good deal you can seek estimates from many difference. Most of the estimates are non-binding though since it is hard to know for sure the exact weight just by looking at the items. If you obtain a binding quote, it would usually cost higher because the company would surely put an allowance to ensure they will not lose money over the transaction.
In many instances your things may be transported together with other people's belongings. This would even make the move less expensive for you man and van.