Oracle AS 10g (10.1.2.0.2) is a de-supported version now. So you cannot find the installers in Oracle website.
If you need this software, please open a SR with Oracle.
You cannot run Forms and Reports 10.1.2.0.2 using weblogic 10.3.
There are Forms and Reports installers of 11g available which can be used with Weblogic 10.3.x version.
Yes Weblogic 10.3.1 is certified with Forms and reports 18.104.22.168.0.
For mote information on certifications of Weblogic and FMW please refer to the below note :-
note:1073776.1 "Steps to Maintain Oracle Fusion Middleware 11g Release 1 (11.1.1)"
Table 2: Oracle Fusion Middleware 11g Releases