It can be sufficient but it would be easier for you to download .netbeans witn j2me support.
wtk is integrated and you can also use some of advanced features like debugging etc.
For simple app phone model is not important as long as it has midp2.0 and cldc 1.1 support.
If you want to develop app only for that model you can download sdk from sonyericsson dev site.
Yes, you can send .jar file from comp. to phone by bluetooth. On some phones installation starts immediately.
I don't think it matters what version of Java you have installed. JME has its own JVM and its own set of classes, which are not the same as those that come with the standard JDKs. I forget if the WTK includes a compiler, but you can't use any of the standard JDK runtime stuff in a mobile app - you have to use their WTK equivalents (if any).
An IDE is no substitute for an Intelligent Developer.
I searched and it seems that sony ericsson w810i supports midp2.0 and cldc 1.1 support.
So now I know that I should be able to develop an app and deploy it on my cell.
I faced one problem today:
After downloading Sun Java Wireless Toolkit for CLDC, 2.5.1 it tried to push one WTK2.51 sample applcation to my cell from my pc using bluetooth dongle but the transfer did not happen.
I tried sending the sample applications .jar and its .jad file and it said operation failed.
How do I work around this?
Before I can attempt to develop a j2me app I need to be sure I can install it on my cell.